Flexible koala conservation on private land under climate change

Flexible adaptation

7,000ha koala habitat on private land

Koala habitat: KITL index > 0.25

Flexible adaptation 50% more cost-effective

Flexibility: adding protection more valuable than ending

Key findings

Appendix 1: Sensitivity analysis

Sensitivities of estimates of the value of flexibility (A, E and A/E) under changes to the default parameters, showing sensitivities to a, sampling of 10 study populations randomly sampled with the stratified sampling approach (default index = 1), b, year covenant modification is allowed - t’ (default = 2050). c, koala landscape capacity indicator cut-off (default = 0.25) across a range of cut-offs where feasible solutions to the problem are found, and d. Amount of learning based on the number of climate scenarios decision-makers are uncertain about (1 being perfect certainty over climate change, default = 12), with “No Learning”, “Partial Learning” and “Full Learning” having parameters of 12, 3 and 1 respectively.

Appendix 2: Two-stage stochastic optimization

\[ \min_x E_{j \in J}\Big[\sum_i \sum_t c_{ijt}x_i + E_{S\in\xi}[Q(x,S)]\Big] \\ Q_j(x,S) := \min_{y,w} E_{s\in S}\Big[\sum_i \sum_{t\geq t'} c_{ijt}y_{is} - c_{ijt}w_{is}\Big] \\ s.t. \sum_i m_{ijts} x_i \geq K \quad \forall t=1,s\in S, j \in J \\ \sum_i m_{ijts}(x_i + y_{is} - w_{is} \geq K \quad \forall t \geq t', s \in S, j \in J \\ \sum_i m_{ijts} x_i \geq K \quad \forall t = 1, s \in S, j \in J \\ x_i + y_{is} \leq 1 \quad \forall i \in N, s \in S \\ x_i \geq w_{is} \quad \forall i \in N, s \in S \\ y_{is} = 0 \quad \forall i \in N, s \in S \\ w_{is} = 0 \quad \forall i \in N, s \in S \\ x,y,w \in [0,1] \]

Appendix 3

Conservation under Current Conditions (CC)

• Total habitat reaches 7,000 ha in 2020 on average

Robust and Inflexible (RI)

• Total habitat is higher than 7,000 for all time-steps, all climate scenarios and all social behavior realizations
• Covenant offers same across time

Flexible (F)

• Total habitat is higher than 7,000 for all time-steps, all climate scenarios and all social behavior realizations
• New covenant offers can be added in 2050

Flexible with Learning (F+L)

• Total habitat is higher than 7,000 for time-steps before 2050, all climate scenarios and all social behavior realizations
• After 2050, total habitat must be higher than 7,000 for a particular climate scenario (offers can be different across scenarios) on the average social behavior realization
• New covenant offers can be added in 2050